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Biomedical subjects

R N Anderson

Publications and source records attributed to R N Anderson.

32 records · Page 2Linked to original sources
PubMed1997

Annual summary of vital statistics--1996.

Several recent trends in the vital statistics of the United States continued in 1996, including an increase in life expectancy and declines in infant mortality, births to teenage mothers, age-adjusted death rates, and death rates for children and adolescents. In 1996, there were an estimated 3 914 953 births in the United States. The preliminary birth rate remained unchanged at 14.8 births per 1000 population, and the fertility rate, births per 1000 women 15 to 44 years of age, was essentially the same at 65.7. Fertility rates rose slightly for most racial and ethnic groups except black women, for whom the rate hit a historic low of 70.8. Overall, fertility remains particularly high for Hispanic women, although there is considerable variation within this heterogenous group. For the fifth consecutive year, birth rates dropped for teenagers. Birth rates for women >/=30 years of age continued to increase. The birth rate for unmarried women declined 1% in 1996 to 44.6 births per 1000 unmarried women, continuing the decline noted in 1995 for the first time in 2 decades. The percentage of women who began prenatal care in the first trimester rose in 1996 to 81.8%, whereas the percentage with late (third trimester) or no care dropped to 4.1%. The rise in timely prenatal care was greatest for black and Hispanic women. The percentage of low birth weight (LBW) infants reached 7.4% in 1996, its highest level since 1975. The very low birth weight rate remained unchanged at 1.4%. The rise in LBW occurred primarily among white women, whereas the LBW rate for black women dropped to 13.0%, the lowest rate reported since 1987. The rise among white women is only partially a result of increases in multiple births, because LBW rates have also risen among white singleton births. The multiple birth ratio rose again in 1996 by 2%, as it has since 1980. The rise was particularly large for higher-order multiple births. Infant mortality reached an all time low level of 7.2 deaths per 1000 births, based on preliminary 1996 data. Neonatal and postneonatal rates declined, as did rates for both black and white infants. National birth weight specific mortality rates are reported here for the first time. In 1995, 63% of infant deaths occurred to the 7.3% of the population that was born LBW. The four leading cause of infant death were congenital anomalies, disorders relating to short gestation and unspecified birth weight, sudden infant death syndrome, and respiratory distress syndrome, accounting for more than half of infant deaths in 1996. Despite the declines in infant mortality, the United States continues to rank poorly in international comparisons of infant mortality. Expectation of life at birth reached a new high in 1996 of 76.1 years for all gender and race groups combined. Age-adjusted mortality rates declined in 1996 for diseases of the heart, malignant neoplasms, cerebrovascular diseases, accidents and adverse effects, chronic liver disease and cirrhosis, and suicide. They rose, as in the past several years, for chronic obstructive pulmonary diseases, diabetes mellitus, and pneumonia and influenza. For the first time since human immunodeficiency virus infection was created as a special cause-of-death category in 1987, death rates for human immunodeficiency virus infection declined from 15.6 in 1995 to 11.6 in 1996. The homicide rate also declined, as it has since 1991. Death rates for children between 1 and 19 years of age declined in 1996, with an estimated 29 183 deaths to children. Unintentional injury mortality has dropped by approximately 50% among children and adolescents since 1979, although it remains the leading cause of death for all age groups of children from 1 to 19 years. Homicide was the fourth leading cause of death for children 1 to 4 and 5 to 9 years of age, the third leading cause for children 10 to 14, and the second leading cause for 15 to 19 year olds.

Adolescent↗
PubMed1984

Temporal evolution of body surface map patterns following acute inferior myocardial infarction.

We studied the evolution of body-surface potential map (BSPM) patterns in 32 patients following first acute inferior myocardial infarction. Initial BSPMs were obtained at a mean of 79 hours post-infarction; follow-up BSPMs, a mean of eight months post-infarction. Temporal area-of-difference maps, constructed by subtracting initial from follow-up group-mean BSPMs, revealed reciprocal changes over the superior and inferior torso for both Q-zone and ST-segment time-integral distributions. The temporal changes in Q-zone patterns were small but definite: over the inferior torso there was a relative gain in Q-zone values and, over the superior torso, a relative decrease. In contrast, there were marked spatial and quantitative changes of ST-segment distributions during the follow-up period. Over the superior torso, particularly anteriorly, there was a gain in ST-segment values; over the inferior torso, a decrease. With the small temporal changes in Q-zone time-integral distributions, individual Q-zone maps continued to reflect a pattern of inferior myocardial infarction at follow-up. In contrast, the marked temporal changes in ST-segment time-integral distributions resulted in individual map patterns at follow-up that were nearly indistinguishable from normal ST-segment maps. The relatively small changes in depolarization time-integral patterns during the early post-infarction period suggest that the Q-zone patterns of the acute phase of myocardial infarction reflect near-irreversible or completed myocardial damage. The marked normalization of repolarization time-integral patterns during the recovery phase suggests, however, that there are also considerable areas of myocardium-at-risk during the early phase of the infarction process which stabilize with time.

Adult↗
PubMedDate not supplied

Why IFR (instrument flight rules)?

INTRODUCTION: Air medical services can use aircraft equipped to fly under visual flight rules (VFR) or instrument flight rules (IFR). IFR allows the pilot to fly safely into lower weather minimums, potentially increasing the number of EMS flights that can be completed. We examined the advantages and disadvantages of both methods of helicopter flight, the potential service gain with IFR capability, and the financial feasibility of using IFR in an urban air medical program. METHODS: Retrospective data were collected on the number of missed flights for Vanderbilt LifeFlight during a 6-year period. Focusing on 2 recent years, we examined the number of flights missed because of weather. Data were prospectively obtained on missed flights that could have been completed with IFR from April 1997 to March 1998. Financial estimates were calculated to determine the revenue potential of an IFR program. RESULTS: An average of 24% of flights were missed from 1991 to 1997. In 1996-97, primary reasons for missed flights included poor visibility and low clouds, conditions in which IFR capable helicopters could fly. Prospective data from 1997-98 indicated an average of 6.7 missed flights per month potentially could have been completed with IFR. Analysis of expenses and revenue suggest that converting a ship from VFR to IFR, which involves both equipment purchases and pilot training, is economically feasible given the potential revenue gained by the number of flights completed during marginal weather conditions. CONCLUSION: Implementing an IFR program increases the safety margin and allows better EMS service to the community.

Air Ambulances↗